Y₃Al₅−xGaxO₁₂:Cr³⁺: A novel red persistent phosphor with high brightness

We report on red persistent phosphors of Y 3 Al 5− x Ga x O 12 :Cr 3+ garnet (YAGG:Cr 3+ , x from 0 to 5). In these materials, Cr ions act as both emission centers and electron traps. The trap depth, which is regarded as the energy gap between the bottom of the conduction band and the electron trap, can be optimized by modifying the Ga 3+ substitution content ( x ). After ceasing UV illumination, the persistent luminescence of the YAGG:Cr 3+ ( x = 3) phosphor was nearly 5 times higher than that of the widely used ZnGa 2 O 4 :Cr 3+ red persistent phosphor. Such novel red persistent phosphors have great potential for an improved in vivo bioimaging application.